Combined stop/turn/tail/clearance lamp using light emitting diode technology

ABSTRACT

A tail/stop lamp assembly is disclosed that uses as a light source light emitting diodes, specifically SnapLEDs™. The tail/stop lamp assembly is composed of housing, a lens, and a SnapLED™ array. The lens is composed of six different optical units surrounded by Fresnel rings. The housing is of a very slim design. The combination of optics and housing is a stylish, sturdy and efficient tail/stop lamp assembly that complies with Society of Automotive Engineers (SAE) standards.

PRIORITY STATEMENT

[0001] This application claims the benefit of U.S. provisional application Ser. No. 60/229,229 filed Aug. 31, 2001.

FIELD OF THE INVENTION

[0002] The present invention relates to an LED-illuminated vehicular lamp. In particular, the invention describes a combined stop/turn/tail/clearance light assembly, which utilizes light emitting diode technology as the light source.

BACKGROUND ART

[0003] Advances in light emitting diodes have provided for the development of numerous applications. The first uses of light emitting diodes were as status indicator lights to signal on and off in electronic equipment. This limited use was a consequence of the fact that LEDs were unable to produce ample light for applications requiring greater light intensity or distribution. Light emitting diodes could be used in other applications; however, the quantity of light emitting diodes that had to be utilized made other applications cost prohibitive. Advances in the design of light emitting diodes allow for the creation of traffic lights, commercial signs, vehicular marker/clearance lights and high mounted stop lamps.

[0004] Light emitting diodes, such as those manufactured by Hewlett Packard and marked with the SnapLED™ trademark are mounted to the flexible substrate through the use of a patented solderless clinch technology, such as described in U.S. Pat. Nos. 5,519,596 and 5,404,282. One characteristic of a SnapLED™ diode array is that the drive circuit is usually mounted in the wire harness or on a remote printed board. One advantage of this remote location is that it isolates the heat generated by the drive circuit from the light emitting diode array. As one skilled in the art is aware, heat can damage light emitting diodes.

[0005] The SnapLED™ is also more efficient in producing light, resulting in an ability to use a lower number of diodes for an application. This design feature allows for more freedom and creativity in the plan of vehicular lamps, since problems like heat dissipation or high number of light emitting diodes are no longer an issue. In addition, the SnapLED™ technology allows for a lower cost LED lamp, since the lamp does not require a large number of LEDs to meet standards or specifications. In addition, the use of the SnapLED™ technology requires the use of optical elements in the lens of a vehicles' lamp in order to meet, or exceed, the specifications set by the U.S. Department of Transportation.

[0006] U.S. Pat. No. 2,254,961 discloses the use of a unitary lens, light and reflector system in which an outwardly curved portion (bubble shape) is present in the center of the lens.

[0007] U.S. Pat. No. 3,633,022 is generally directed to a lamp having a lens, a light source, and a reflector. The lens has an outer surface that acts as a dispersing lens. A double concave cylindrical lens with a double grooved shape forms the dispersing element.

[0008] U.S. Pat. No. 4,153,928 concerns a lens assembly for a vehicle tail lamp, which is attached to a housing provided with a reflector and a light bulb. The lens assembly is composed of two lenses, an inner and an outer lens. Each lens is composed of a plurality of optical ribs. The design of this lens requires that a bulb and a reflector be used. The lens will not work with light emitting diode technology that does not require a reflector or a deep cavity to accommodate a bulb.

[0009] U.S. Pat. No. 5,013,144 discloses a light-emitting diode lamp that is formed by two ellipses, which if extended would meet directly above the light-emitting diode. There is a slight depression where the two sections of the lens meets, which is filled with a clear substance to provide ease of manufacturing. This design for a light emitting diode lamp is bulky. In addition, the lens is not well protected as it protrudes from the housing of the lamp.

[0010] U.S. Pat. No. 5,692,827 illustrates a rear lighting system to be used with a wide variety of light sources. The invention refers to an elongated light source and a solid lens having an inner hyperbolic surface with the curvature toward the light source. The outward-facing surface has a plurality of generally stepped planar surfaces with fluting. This invention is designed to provide a small package depth while providing a uniform light distribution. This design is not made exclusively to take advantage of SnapLED™ technology. Indeed, because of the design of the housing, this lamp cannot take advantage of the remote location of the circuit board that is characteristic of the SnapLED™ technology. The design also contemplates non-compatible light sources, such as a neon tube, such that the design will not work with SnapLED™ technology.

[0011] U.S. Pat. No. 5,765,940 teaches a light emitting diode-illuminated stop/tail lamp assembly. The patent shows a lamp assembly with a lens design that, when in use with selected light emitting diodes, minimizes power requirements and heat dissipation needs. The lens in this patent is composed of hyperbolic surfaces. It can also include vertically extending grooves. A complicated circuit is required to power the numerous light emitting diodes used. A disadvantage of this design is the additional components to control heat dissipation and power dissipation. The large numbers of light emitting diodes and circuit components required make the '940 lamp assembly expensive, complicated, and not accessible to the common consumer.

[0012] Most of the designs in the prior art for vehicular lamps such as tail/stop lamps are not designed specifically to take advantage of the SnapLED technology. Therefore, a need arises for a specific lamp design to take advantage of the additional capabilities of SnapLED™ technology. The tail/stop lamp disclosed herein is specifically designed to take advantage of SnapLED™ technology and to solve the problems present in the prior art.

[0013] Accordingly, it is an object of the present invention to utilize SnapLED™ technology in a combined stop/tail/turn/clearance lamp for vehicles.

[0014] It is an additional object of the present invention to provide a combined stop/tail/turn/clearance lamp for vehicles that distributes light emitting from SnapLED™ diodes to simultaneously meet Society of Automotive Engineers Standards J585e (September 1997), J1398 (May 1995), J592e (July 1972).

[0015] It is a further object of the present invention to provide a lens for a combined stop/tail/turn/clearance lamp for vehicles that has a unique combination of optical elements designed to distribute light over a specified range and at a specified intensity.

[0016] In addition, it is an object of the present invention to provide a housing with one way mounting terminals to mate with a SnapLED™ diode array's mounting tabs and a printed circuit board's mounting posts such that the diode array may be mounted to the housing. The one way mounting terminals operate such that the array can be mounted once but cannot be removed and remounted without destroying the mounting terminals.

[0017] Further, it is an object of the present invention to provide one way attachment terminals on a printed circuit board to mate with a SnapLED™ diode array's attachment posts such that the diode array may be operatively connected to the printed circuit board. The one way attachment terminals operate such that the array can be operatively connected once but cannot be removed and remounted without destroying the attachment terminals.

[0018] Lastly, it is an object of the present invention to provide a combined stop/tail/turn/clearance lamp for vehicles wherein the control circuit for the lamp is located remotely from the lamp.

[0019] These and other objects of the invention will become more apparent from the following detailed description and the accompanying drawings.

SUMMARY OF THE INVENTION

[0020] The combined stop/tail/turn/clearance lamp design presented herein has a number of features that take advantage of SnapLED™ light emitting diode technology. In the preferred embodiment, the lamp possesses a lens specifically designed to be used with SnapLED™ technology. The lens is composed of a combination of different optical elements including Fresnel rings. The combination of the different optical elements ensures proper distribution and intensity of light in accordance with the regulations for vehicular lamps. Another advantage of the combination of optical elements is that the SnapLED™ diode array does not have to be aligned into an exact position to produce an accurate and efficient lamp. Thus, as it is designed to do, the SnapLED™ diode array can move around slightly, while not affecting the distribution and intensity of the light emitted from the lamp.

[0021] In a preferred embodiment of the design, the SnapLED™ diode array is encapsulated with a potting compound that surrounds the array within the housing. The embedding of the array provides durability, reliability and stabilizes the array while it is subject to the mechanical vibrations that result from the operation of the vehicle. The embedding of the array also protects the array from corrosion that can be caused by water contacting the metal support frames of the diode array. In addition, the embedding of the diode array prevents unwanted electrical connections or paths that can form under various environmental conditions in the spaces between the metal support frames of the diode array. The housing is designed with a flange around the lens to give strength, protection and support to the lens and lamp. The lens of the lamp is approximately flush with the housing. The lamp can be attached to the vehicle in various ways, preferably, through a post.

[0022] The SnapLED™ diode array is embedded with a potting compound, such as an epoxy resin, inside the housing to provide extra protection and keep the array from jostling out of position due to the extreme mechanical vibrations typical in moving vehicles. In a preferred embodiment, the present invention is circular in shape.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other aspects, objects, and advantages of the present invention appear more clearly on reading the following best mode for carrying out the invention, given by way of example and made with reference to the accompanying drawings, in which:

[0024]FIG. 1 is a three-dimensional view of a preferred embodiment of the present invention.

[0025]FIG. 2 is a top view of a preferred embodiment of the present invention.

[0026]FIGS. 3 A, B, and C are cross sectional views of the various optical elements that are utilized in the preferred embodiment of the present invention.

[0027]FIG. 4 depicts a side view of the SnapLED™ diode array connected to the printed circuit board as utilized in the preferred embodiment of the invention.

[0028]FIG. 5 depicts a top view of the SnapLED™ diode array, utilized in the preferred embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0029] For the purpose of promoting an understanding of the present invention, reference will be made to an embodiment of a circular stop/tail/turn/clearance lamp as illustrated in the drawings. It will nevertheless be understood that no limitations of the scope of the invention is thereby intended, such alterations as changing the geometry of the invention or changing the placement of the various optical elements of the lens could provide additional alterations which would fall within the spirit and scope of the invention described herein. Some of the possible alterations will be mentioned in the following description.

[0030] With particular reference to the drawings, the reader should understand that like numerals in different figures refer to the same elements of the invention.

[0031]FIG. 1 shows a three-dimensional view of the lamp 10. The lamp is comprised of a housing 20, a flexible metal support 80 (not shown) light emitting diodes 100 (not shown), a printed circuit board 90 (not shown) and a lens 30. The housing 20 contains a plurality of holes 21 for receiving fasteners for fixedly securing the lamp to the vehicle. The housing 20 also possesses a plug 22 that mates with the vehicle to connect the lamp 10 to the electrical system of the vehicle.

[0032]FIG. 1 also depicts the lens 30 and the preferred embodiment of the combination of the different optical elements 50, 60, and 70. The lens has a face and a back. The face of the lens is smooth and is exposed to the environment. As shown in FIG. 1, a set of Fresnel rings 40 surrounds each of the optical elements 50, 60 and 70. The Fresnel rings 40 are formed as tiny grooves in the back of the lens 30. The Fresnel rings 40 act as refracting surfaces, sending parallel rays of light emitted from the light emitting diodes to a common focus.

[0033] The lens 30 also possesses a number of different types of optical elements. The types of optical elements are generally shown in FIGS. 1 and 2, while a detailed cross-section is shown in FIGS. 3A, B, and C. The first type of element, the flat optical element 60 shown in FIG. 3A, has a flat surface at the center of the optical element 60. The flat surface is textured to provide a surface to randomly scatter light emitted from the light emitting diodes. A set of rounded off wedges 62 spaced slightly apart, surrounds the optical element, before the Fresnel rings 40 begin. The rounded-off wedges 62 spread the substantially parallel light emitted from the light emitting diodes out as far as forty-five (45) degrees to the left and to the right. Surrounding the rounded-off wedges 62 is a set of Fresnel rings 40.

[0034] The second type of optical element, the lined optical element 70 as shown in FIG. 3B, has a set of grooves 71 cut into the optical element. The set of grooves refracts the substantially parallel light emitted from the light emitting diode to the right and left approximately forty-five (45) degrees. Rounded-off wedges 72 surround the optical element. The rounded off wedges 72 further act to spread the light to the right and to the left. Surrounding the rounded off wedges 72 are Fresnel rings 40.

[0035] The third type of optical element, the curved optical element 50 shown in FIG. 3C, has a curved portion 51 which originates from a rounded-off wedge 53 and curves to the center of the optical element. A flat portion 52 meets the curved portion 51 and joins the rounded off wedge 53. The flat and curved portions of the optical element are textured to provide a surface to scatter light emitted from the light emitting diodes randomly. The rounded off wedges 53 surrounding the optical element spread the substantially parallel light emitted from the light emitting diodes out as far as forth-five (45) degrees to the left and to the right. Surrounding the wedges 53 is a set of Fresnel rings 40.

[0036] As is shown in FIGS. 1 and 2, the preferred embodiment of the invention utilizes six light emitting diodes. It should be understood that any number of light emitting diodes can be used, depending on the standards/specifications one attempts to meet. The center of an optical element is positioned above a light emitting diode. Thus, in the preferred embodiment, six optical elements, chosen from the three types of optical elements are utilized. In the most preferred embodiment, the arrangement, of the different optical elements, is as follows: The flat optical element 60 is positioned in the center of the lens 30. A first curved optical element 50 is positioned toward the outer edge of the lens 30.,

[0037] Proceeding clockwise from the curved optical element 50, a first lined optical element 70 is positioned, again toward the outer edge of the lens.

[0038] Moving clockwise from the first lined optical element 70, a second lined optical element 70 is located toward the outer edge of the lens 30. The second optical element is, however, rotated ninety (90) degrees such that the lines of the lined optical element extend in direction perpendicular to that of the first lined optical element 70.

[0039] Advancing clockwise from the second lined element 70, a second curved optical element 50 is placed toward the outer edge of the lens 30. The last element proceeding clockwise from the second curved optical element is a third lined optical element 70, arranged in a similar fashion as the second lined element, such that the lines of element are vertical.

[0040]FIG. 4 depicts the flexible metal supports 80 to which are mounted the light emitting diodes. FIG. 4 also depicts the attachment posts 81 that form the connection between the flexible metal supports 80 and the printed circuit board 90. In addition, FIG. 4 shows the mounting posts 91 that are used to attach the printed circuit board to the electrical connections of the vehicle.

[0041]FIG. 5 depicts a front view of the SnapLED™ diode array including the flexible metal supports 80, the LEDs 100, the attachment posts 81, and the mounting tab 82. The mounting tabs 82 are used to secure the flexible supports 80 to the housing 20 through one-way mounting terminals on the housing. Because the mounting terminals are one-way terminals, the flexible metal supports 80 cannot be removed without destroying the mounting terminals and the mounting tabs.

[0042] The attachment posts 81 of the flexible metal supports 80 are also connected to one-way attachment terminals on the printed circuit board 90. Again, once the attachment posts are connected, they cannot be removed without destroying the terminals or the posts. It should be understood that any type of printed circuit board can be used with this invention; however, the attachment terminals must be embedded in the board.

[0043] The description presented in the preferred embodiments above is not intended to demonstrate all of the possible arrangements and modifications to this design. For those skilled in the art, changes will be apparent that will fall within the scope of the present invention. 

What is claimed:
 1. A lamp assembly comprising: a housing; a printed circuit board; a flexible support operatively connected to said printed circuit board; at least one light emitting diode operatively connected to said flexible support; a lens for transmitting light emitted from said at least one light emitting diode.
 2. A lamp assembly according to claim 1 further comprising potting material covering the flexible support and at least part of said at least one light emitting diode.
 3. A lamp assembly according to claim 2 wherein said potting material is an epoxy.
 4. A lamp assembly according to claim 1 further comprising a flange to permit mounting of said lamp assembly.
 5. A lamp assembly according to claim 4 wherein said flange is adapted to receive a fastener.
 6. A lamp assembly according to claim 1 wherein said lamp assembly meets the minimum photometric requirements of Society of Automotive Engineers' Standards J585e, J1398, and J592e.
 7. A lamp assembly comprising: a housing; a printed circuit board; a flexible support operatively connected to said printed circuit board; at least one light emitting diode operatively connected to said flexible support; and, a lens for transmitting light emitted from said at least one light emitting diode; said lens having at least one optical element.
 8. A lamp assembly according to claim 7 further comprising potting material covering the flexible support and at least part of said at least one light emitting diode.
 9. A lamp assembly according to claim 8 wherein said potting material is an epoxy.
 10. A lamp assembly according to claim 7 further comprising a flange to permit mounting of said assembly.
 11. A lamp assembly according to claim 10 wherein said flange is adapted to receive a fastener.
 12. A lamp assembly according to claim 7 wherein said lamp meets the minimum photometric requirements of Society of Automotive Engineers' Standards J585e, J1398, and J592e.
 13. A lamp assembly comprising: a housing; a printed circuit board; a flexible support operatively connected to said printed circuit board; at least one light emitting diode operatively connected to said flexible support; and, a lens for transmitting light from said at least one light emitting diode, said lens having, a first optical element to scatter said light; a second optical element to spread said light at an angle substantially 45° to the left and right of the longitudinal axis of said at least one light emitting diode; and, a third optical element to scatter said light.
 14. A lamp assembly according to claim 13 further comprising potting material covering the flexible support and at least part of said at least one light emitting diode.
 15. A lamp assembly according to claim 14 wherein said potting material is an epoxy.
 16. A lamp assembly according to claim 13 further comprising a flange to permit mounting of said assembly.
 17. A lamp assembly according to claim 16 wherein said flange is adapted to receive a fastener.
 18. A lamp assembly according to claim 13 wherein said lamp meets the minimum photometric requirements of Society of Automotive Engineers' Standards J585e, J1398, and J592e. 19.A lamp assembly comprising: a housing; a printed circuit board; a flexible support operatively connected to said printed circuit board; at least one light emitting diode operatively connected to said flexible support; and, a lens for transmitting light from said at least one light emitting diode, said lens having, a first optical element to scatter said light; a second optical element to spread said light at an angle substantially 45° to the left and right of the longitudinal axis of said at least one light emitting diode; a third optical element to scatter said light; and, a fourth optical element to refract said light into a common focus.
 20. A lamp assembly according to claim 19 further comprising potting material covering the flexible support and at least part of said at least one light emitting diode.
 21. A lamp assembly according to claim 20 wherein said potting material is an epoxy.
 22. A lamp assembly according to claim 19 further comprising a flange to permit mounting of said assembly.
 23. A lamp assembly according to claim 22 wherein said flange is adapted to receive a fastener.
 24. A lamp assembly according to claim 19 wherein said lamp meets the minimum photometric requirements of Society of Automotive Engineers' Standards J585e, J1398, and J592e. 